var path = require('path');
var config = require('./config').prod;
var utils = require('./scripts/utils');
var webpack = require('webpack');
var merge = require('lodash.merge');
var baseWebpackConfig = require('./webpack.base.conf');
var ExtractTextPlugin = require('extract-text-webpack-plugin');

var webpackConfig = merge(baseWebpackConfig, {
  devtool: false,
  output: merge(baseWebpackConfig.output, {
    filename: utils.assetsPath('js/[name].[chunkhash].js'),
    chunkFilename: utils.assetsPath('js/[id].[chunkhash].js'),
  }),
  plugins: baseWebpackConfig.plugins.concat([
    new webpack.optimize.UglifyJsPlugin({
      compress: {
        warnings: false
      }
    }),
    new webpack.optimize.OccurenceOrderPlugin(),
    // extract css into its own file
    new ExtractTextPlugin(utils.assetsPath('css/[name].[contenthash].css')),
    // split vendor js into its own file
    new webpack.optimize.CommonsChunkPlugin({
      name: 'vendor',
      minChunks: function (module, count) {
        // any required modules inside node_modules are extracted to vendor
        return (
          module.resource &&
          /\.js$/.test(module.resource) &&
          module.resource.indexOf(
            path.join(__dirname, 'node_modules')
          ) === 0
        )
      }
    }),
    // extract webpack runtime and module manifest to its own file in order to
    // prevent vendor hash from being updated whenever app bundle is updated
    new webpack.optimize.CommonsChunkPlugin({
      name: 'manifest',
      chunks: ['vendor']
    })
  ])
});

if (config.productionGzip) {
  var CompressionWebpackPlugin = require('compression-webpack-plugin');
  webpackConfig.plugins.push(
    new CompressionWebpackPlugin({
      asset: '[path].gz[query]',
      algorithm: 'gzip',
      test: new RegExp(
        '\\.(' +
        config.productionGzipExtensions.join('|') +
        ')$'
      ),
      threshold: 10240,
      minRatio: 0.8
    })
  );
}

module.exports = webpackConfig;
